Zobrazeno 1 - 10
of 64
pro vyhledávání: '"Ohnaka, Keiichi"'
Mass loss at the asymptotic giant branch (AGB) plays an important role not only in the final fates of stars, but also in the chemical evolution of galaxies. Nevertheless, the metallicity effects on AGB mass loss are not yet fully understood. We prese
Externí odkaz:
http://arxiv.org/abs/2403.03287
Publikováno v:
A&A, 643, A175 (2020)
The asymptotic giant branch (AGB) star HR3126, associated with the arcminute-scale bipolar Toby Jug Nebula, provides a rare opportunity to study the emergence of bipolar structures at the end of the AGB phase. We carried out long-baseline interferome
Externí odkaz:
http://arxiv.org/abs/2012.00768
The mechanism of mass loss in late evolutionary stages of low- and intermediate-mass stars is not yet well understood. Therefore, it is crucial to study the dynamics of the region within a few stellar radii, where the wind acceleration is considered
Externí odkaz:
http://arxiv.org/abs/1908.06997
Molecules and dust produced by the atmospheres of cool evolved stars contribute to a significant amount of the total material found in the interstellar medium. To understand the mechanism behind the mass loss of these stars, it is of pivotal importan
Externí odkaz:
http://arxiv.org/abs/1907.08693
Autor:
Adam, Christian, Ohnaka, Keiichi
Publikováno v:
A&A 628, A132 (2019)
Low- and intermediate-mass stars at the asymptotic giant branch (AGB) are known to be prevalent dust providers to galaxies. However, the mechanisms responsible for the formation and acceleration of dust in the cool extended atmospheres of AGB stars a
Externí odkaz:
http://arxiv.org/abs/1907.05534
Autor:
Rau, Gioia, Montez Jr., Rodolfo, Carpenter, Kenneth G., Wittkowski, Markus, Bladh, Sara, Karovska, Margarita, Airapetian, Vladimir, Ayres, Tom, Boyer, Martha, Chiavassa, Andrea, Clayton, Geoffrey, Danchi, William, De Marco, Orsola, Dupree, Andrea K., Kaminski, Tomasz, Kastner, Joel H., Kerschbaum, Franz, Linsky, Jeffrey, Lopez, Bruno, Monnier, John, Montargès, Miguel, Nielsen, Krister, Ohnaka, Keiichi, Ramstedt, Sofia, Roettenbacher, Rachael, Brummelaar, Theo ten, Paladini, C., Sarangi, Arkaprabha, van Belle, Gerard, Ventura, Paolo
Cool, evolved stars are the main source of chemical enrichment of the interstellar medium (ISM), and understanding their mass loss and structure offers a unique opportunity to study the cycle of matter in the Universe. Pulsation, convection, and othe
Externí odkaz:
http://arxiv.org/abs/1903.04585
Autor:
Homan, Ward, Richards, Anita, Decin, Leen, Kervella, Pierre, de Koter, Alex, McDonald, Iain, Ohnaka, Keiichi
Publikováno v:
Astronomy & Astrophysics, 05/2017, Volume 601, id.A5, 19 pp
The circumstellar environment of the AGB star L$_{\rm 2}$ Puppis was observed with ALMA in cycle 3, with a resolution of $15 \times 18 \rm\ mas$. The molecular emission shows a differentially rotating disk, inclined to a nearly edge-on position. In t
Externí odkaz:
http://arxiv.org/abs/1803.05222
Autor:
Kervella, Pierre, Decin, Leen, Richards, Anita M. S., Harper, Graham M., McDonald, Iain, O'Gorman, Eamon, Montargès, Miguel, Homan, Ward, Ohnaka, Keiichi
Publikováno v:
A&A 609, A67 (2018)
We observed Betelgeuse using ALMA's extended configuration in band 7 (f~340 GHz, {\lambda}~0.88 mm), resulting in a very high angular resolution of 18 mas. Using a solid body rotation model of the 28SiO(v=2,J=8-7) line emission, we show that the supe
Externí odkaz:
http://arxiv.org/abs/1711.07983
Autor:
Stee, Philippe, Allard, France, Benisty, Myriam, Bigot, Lionel, Blind, Nicolas, Boffin, Henri, Fernandes, Marcelo Borges, Carciofi, Alex, Chiavassa, Andrea, Creevey, Orlagh, Cruzalebes, Pierre, de Wit, Willem-Jan, de Souza, Armando Domiciano, Elvis, Martin, Fabas, Nicolas, Faes, Daniel, Gallenne, Alexandre, Pena, Carlos Guerrero, Hillen, Michel, Hoenig, Sebastian, Ireland, Michael, Kervella, Pierre, Kishimoto, Makoto, Kostogryz, Nadia, Kraus, Stefan, Labeyrie, Antoine, Bouquin, Jean-Baptiste Le, Lebre, Agnès, Ligi, Roxanne, Marconi, Alessandro, Marsh, Thomas, Meilland, Anthony, Millour, Florentin, Monnier, John, Mourard, Denis, Nardetto, Nicolas, Ohnaka, Keiichi, Paladini, Claudia, Perraut, Karine, Perrin, Guy, Petit, Pascal, Petrov, Romain, Rakshit, Suvendu, Schaefer, Gail, Schneider, Jean, Shulyak, Denis, Simon, Michal, Soulez, Ferreol, Steeghs, Danny, Tallon-Bosc, Isabelle, Tallon, Michel, Brummelaar, Theo ten, Thiebaut, Eric, Thévenin, Frédéric, Van Winckel, Hans, Wittkowski, Markus, Zorec, Juan
High spatial resolution is the key for the understanding various astrophysical phenomena. But even with the future E-ELT, single dish instruments are limited to a spatial resolution of about 4 mas in the visible. For the closest objects within our Ga
Externí odkaz:
http://arxiv.org/abs/1703.02395
Publikováno v:
A&A 597, A20 (2017)
Our recent visible polarimetric images of the well-studied AGB star W Hya taken at pre-maximum light (phase 0.92) with VLT/SPHERE-ZIMPOL have revealed clumpy dust clouds close to the star at ~2 Rstar. We present second-epoch SPHERE-ZIMPOL observation
Externí odkaz:
http://arxiv.org/abs/1611.04622